In recent years, the number of patients with atopic dermatitis is rapidly increasing and the ratio of the patients with atopic dermatitis to the patients who see a dermatologist exceeds 30%, and it becomes one of the major dermatitis. Atopic dermatitis is one of the atopic diseases caused by a hereditary factor that readily produces an IgE antibody against a common allergen, in addition to various environmental factors. The disease starts in infancy and runs a course of disease chronically with age, and becomes milder before puberty in many cases. However, in some cases, the disease continues to persist after puberty, and also there are some cases where the disease starts after puberty. Most of the adult cases are particularly intractable, and it is difficult to expect that the disease may go into outgrow with age thereafter. The completed lesions are lichenified, pruritus is severe, which is often spasmodic, and the disease runs a course of exacerbation and remission associated with other atopic diseases to a certain degree.
Much of the pathogenesis of such atopic dermatitis still remains to be clarified, there is still a problem of distinguish the atopic dermatitis from other skin diseases, and the therapeutic method has not been established yet. Conventionally, external use of an adrenal corticosteroid, medication of an antihistamine or a chemical mediator release inhibitor, a dietary therapy in which egg, milk, soybean or the like is eliminated from the cooking ingredients, elimination of antigens such as mites, fungi (mold) and the like from the living environment and the like have been attempted. However, in the case of the medication, since the drug is intended to be used in a child growing up and over a long period of time, there remains a problem of a side effect. In addition, in the dietary therapy or the measures for eliminating antigens in the environment, it is difficult to completely eliminate the antigens, and also there is a problem of a heavy mental burden.
In view of such circumstances, recently, a study in which while the pathogenesis of atopic dermatitis is being elucidated by making full use of the molecular biological knowledge, a therapeutic effect is going to be improved by inhibiting part of its pathogenesis has been conducted. For example, by focusing on the fact that the production of an IgE antibody against an antigen is part of the mechanism of developing the symptoms as described above, a method of alleviating the symptoms by externally applying a substance inhibiting the production of an IgE antibody against an antigen has been proposed (Patent Documents 1 to 3).
In addition, the present inventors have reported on purification and analysis of an antigen contained in sweat in Non-Patent Document 1. In addition, the present inventors have filed a patent application for the invention entitled “atopic dermatitis inducing proteins” (Patent Document 4).    Patent Document 1: JP-A-7-109290    Patent Document 2: JP-A-7-109292    Patent Document 3: JP-A-9-100236    Patent Document 4: WO 03/084991 A1    Non-Patent Document 1: Grant-in-Aid for Scientific Research from The Ministry of Health, Labours and Welfare of Japan on 2002, Annual Report of Research Project for Prevention, Treatment, etc. of Immunological Allergic Diseases (Vol. 1, pp. 101 to 103, issued on March 2003 by The Japanese Ministry of Health, Labour and Welfare)